A projectile fired upward from the Earth's surface will usually slow down, come momentarily to rest, and return to Earth. For a certain initial speed, however it will move upward forever, with its speed gradually decreasing to zero just as its distance from Earth approaches infinity. The initial speed for this case is called escape velocity. You can find the escape velocity v for the Earth or any other planet from which a projectile might be launched using conservation of energy. The projectile of mass m leaves the surface of the body of mass M and radius R with a kinetic energy Ki = mv²/2 and potential energy Ui = -GMm/R. When the projectile reaches infinity, it has zero potential energy and zero kinetic energy since we are seeking the minimum speed for escape. Thus Uf = 0 and Kf = 0. And from conservation of energy,
Ki + Ui = Kf + Uf
mv²/2 -GMm/R = 0
∴ v = √(2GM/R)
This is the expression for escape velocity.
Answer:
Explanation:
3.4 m/s due North, -1.1 m/s due East
Gamma rays are waves of energy that have no charge. TRUE.
Answer:
rad
Explanation:
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= 
∅ =
rad
The minimum resolvable angle =
rad
Kinetic energy is the energy of motion.
The formula for kinetic energy is given as
KE = (0.5) m v²
where m = mass of object , v = speed of object.
an object having some speed and mass will have kinetic energy while an object at rest will not have any kinetic energy since the speed of object at rest is zero.
Since at rest speed is zero. an object has kinetic energy only when it is in motion.